Pain in the patellofemoral joint, or pain in and around the kneecap, is a frequent and increasingly common problem and is particularly troublesome for athletes and young women. Typically, patellofemoral joint pain is dull and aching in character and is generally localized around the patella. Chronic patellofemoral joint pain may also lead to other maladies including tendinitis of the patellar tendon, muscle atrophy and joint arthritis.
One type of patellofemoral joint pain is associated with malalignment of the patella with respect to the trochlear notch in the femur. For instance, the patella may encroach too closely on either the medial or lateral sides of the trochlear notch. A malalignment of this type is referred to as a glide. A similar malalignment occurs when the patella tilts or leans towards the medial or lateral sides of the trochlear notch. In this case the malalignment is referred to as a tilt. A third malalignment type, known as a rotation, occurs when the long axis of the patella fails to follow the long axis of the femur. Finally, anteroposterior malalignment occurs when the inferior pole of the patella is tilted posteriorly when compared to the superior pole. In general, a given patient may exhibit one or more of the four malalignment types within a single knee. Diagnosis and treatment is further complicated by the possibility that a given malalignment may have a different static and dynamic configuration.
Several methods have been developed to treat patellar malalignment. Perhaps the most effective treatment has been the employment of various physical therapy programs designed to stretch the hamstring muscles and increase the strength of the quadriceps muscles. In particular, exercises which strengthen the vastus medialis oblique muscle have been found to be beneficial in correcting patellar malalignment. In practice, however, it has been found that patients often find it difficult to selectively exercise the vastus medialis oblique muscle making the process of increasing the strength of this muscle particularly difficult.
Another treatment method in common use is the employment of a neoprene sleeve shaped to be slipped over the patient's foot and worn over the effected knee. Sleeves of this type often feature an opening for the patient's patella and are generally constructed of 1/8-inch or 1/4-inch neoprene rubber with a nylon outer and inner covering. In use, the neoprene sleeve fits over the patient's knee and reduces excessive lateral (outside) motion of the patella. Use of neoprene sleeves has been found to be effective for treating patella malalignment in a very limited number of cases. The inability of the standard neoprene sleeve to provide an adequate alignment force, however, has limited the effectiveness of the sleeve in most malalignment cases.
A sleeve system which attempts to overcome the inability of the standard sleeve to generate a sufficient aligning force is disclosed in U.S. Pat. No. 4,296,744 which issued to Palumbo for an invention entitled "Dynamic Patellar Brace." The Palumbo device includes the use of a neoprene sleeve with an aperture or hole for location of the patella. In addition, the Palumbo device includes a bracing pad located by a set of straps. In use, the bracing pad is positioned against one side of the patella and the straps are used to pull the patella into alignment.
Although the Palumbo device may be used to create a greater aligning force than would be attainable by the use of a standard sleeve, there are still doubts as to whether the force produced is great enough and particularly whether the aligning force will remain constant as the patient exercises. In greater detail, it may be appreciated that the aligning force used in the Palumbo device is limited by the ability of the bracing pad to apply force to the patella. Since the bracing pad is held in place only by the interaction of the pad material against the skin of the patient, the ability of the bracing pad to align the patella is necessarily limited. Additionally, it may be appreciated that there will be a natural tendency for the bracing pad to slip over the patella during the course of exercise limiting the effectiveness of the bracing pad still further.
A treatment method that overcomes the disadvantages of the Palumbo device is the use of patellofemoral taping, commonly known as the "McConnell Taping Technique." The McConnell Technique applies a series of adhesive tape strips to the patient's knee. The tape strips cross over the patient's patella and wrap around to the back of the knee. By applying the tape strips under tension, a relatively large force may be applied to align the patient's patella. Additionally, the tape strips may be individually aligned for each patient to account for the various malalignment components present in a particular knee. In general, the McConnell Technique has been found to be highly effective at treating a number of different and varying patellar malalignments. The McConnell Technique, however, is subject to a number of disadvantages. In particular, the McConnell Technique is relatively inflexible after the tape has been first applied. In particular, once the series of tapes have been applied to the patient's knee, there is no provision that allows the tapes or the tension in a particular tape to be adjusted to improve effectiveness of the procedure or to correct a mistake in the original application.
Additionally, experience has demonstrated that application of the taping system prescribed by the McConnell Technique is a time consuming process, particularly when performed by the patient. Even when the tapes are correctly applied, there is a possibility that the tapes will become subsequently dislodged, particularly in the case of prolonged exercise and particularly at the point of attachment of the tape with the back of the knee where the tapes are subject to the greatest amount of dynamic stress.
In light of the above, it is an object of the present invention to provide a patellar alignment system that provides an alignment force that is adequate to align a wide range of patellar malalignments. It is another object of the present invention to provide a patellar alignment system that provides an alignment system that may be easily tailorable to individual patients. It is yet another object of the present invention to provide a patellar alignment system that may be easily applied and easily adjusted after application. It is still another object of the present invention to provide a patellar alignment system that is stable even under the rigors present during intense exercise. It is yet another object of the present invention to provide a patellar alignment system that is cost effective to manufacture and relatively simple to operate.